Intra-seasonal variability in the tropics
We are particularly interested in investigating the role ocean-atmosphere interaction in the Madden-Julian Oscillation (MJO). From observations we know that SST variability modulates MJO variability.
Main content
In a recent work [Tseng et al. submitted], we investigate the ocean’s role on MJO using ECHAM5 model coupled with a Sea-Ice-Thermocline mixed layer ocean model (SIT), a model that represents accurately the structure of uppermost layer of the ocean. Experiments testing the sensitivity of MJO to model configurations, to the vertical resolution of the ocean model, to prescribed SST and to an aqua planet over maritime continent, we show that the ocean-atmosphere interaction is a key element of MJO and accurately representing it leads to an improvement of the simulated MJO.
We will continue to pursue the ocean-atmosphere interaction research, working on numerical simulations of MJO events using the WRF mesoscale model, configured as a tropical channel model. We will assess the MJO sensitivity to the model configuration, especially the vertical resolution of the boundary layer as well as the different cumulus schemes and the processes they parameterize. For this work, a coupling between WRF and SIT ocean model is being undertaken, in an attempt to achieve better simulations of Madden-Julian Oscillation.
References:
Tseng, W.-L., B.-J. Tsuang, N. Keenlyside, H.-H. Hsu and C.-Y. Tu, 2012: Ocean-Atmosphere interaction underlies the Madden-Julian Oscillation. Submitted.
Contacts:
Prof. Noel Keenlyside
Dr. Susana Mendes
Dr. Wang-Lin Tseng